Flow indicator



mec., 6, E55 A, WlTTLlN 725944 FLOW INDICATOR Filed Aug. 16, 1952 2 J2J0 J3 United States Patent() FLOW INDICATOR Albert Wittlin, Chicago,Ill. Application August 16, 1952, Serial No. 304,751 Claims. (Cl.116-117) This invention relates to a flow indicator adapted to beinserted in a iluid line so that owof fluid through the line and throughthe indicator may be easily observed. g

This application is a continuation-in-part of my copending applicationSerial No. 45,533, filed August 21, 1948.

Flow indicators of the type disclosed and claimed herein areparticularly useful in refrigerant lines n refrigerator systems forobserving the flow of the uid, its condition and its nature.

Prior ow indicators of this general nature have been somewhat bulkyparticularly in their lateral dimensions and have not always beeneffective in providing a tight seal between the parts of the indicatorand particularly between the transparent tube through which the fluidows for observation and the housing in which the tube is mounted.

The indicator of this invention successfully solves the problems ofproviding a compact yet high capacity ndicator that does not interferewith the ow of uid therethrough and that provides positive and longlasting sealing means for the various parts of the indicator.

The ow indicator of this invention will be described as related to thelembodiment shown in the accompanying drawings. Of the drawings:

Figure 1 is a plan view of an indicator embodying the invention.

Figure 2 is a longitudinal sectional elevation of the indicator takensubstantially through the center thereof.

Figure 3 is a fragmentary enlarged sectional elevational view of theindicator corresponding to aV portion of Figure 2 and showing theleft-hand end of the transparent tube and associated parts.

The indicator shown in the accompanying drawings comprises a protectivemember within which is located a transparent tube 11. Theprotectivemember 1i) includes a central cylinder 12 and couplingfittings or end portions 13 attached thereto and aligned therewith. Thecylinder 12 is provided with diametrically opposed ports 12a throughwhich the tube 11 and its contents may be viewed. The tube 11 ispreferably provided with one or more opaque markings 14 aligned with theports 12a for aiding in observing the flow of fluid.

Each end tting 13 is provided with screw threads 13a on its inner endfor engagement with similar screw threads on the adjacent end of thecylinder 12. The opposite end of each fitting 13 is also provided withscrew threads 13b for attaching the indicator into the fluid line.

As can be seen in Figure 2, each end fitting 13 is provided with acentral passage 13e of relatively large diameter with these passagewaysbeing substantially aligned with each other and with a larger internalpassageway 12b in the central cylinder 12. Each fitting passageway 13eis only slightly smaller in diameter than the inside diameter of thetransparent tube 11 so that unrestricted flow through the indicator isachieved.

The inner end of cach central passageway 13C in a fitting 13 is enlargedas indicated at 13d to provide a chamber defined on its outer end byinwardly extending annular shoulder 13e.

At each end of the transparent tube 11 there is provided aideformablegasket 15 adapted to make sealing engagement with the end edges of thetransparent tube 11. Each gasket is held in place against the end edgeof the tube by means of an annular washer 16 provided with an annularliange 16a located inwardly of the washer and extending toward thecenter of the tube. Each washer bears against the side of the gasket onthe side opposite to that contacting the tube 11. A helical compressionspring 17 is provided between each shoulder portion 13e and the adjacentwasher 16 forcing the washer 16 toward the tube 11 to hold the gasket 15against the tube.

As is shown most clearly in Figure 3, the outer annular edge part 15a isarranged in sealing engagement with the protective member 10. Thissealing engagement is provided by clamping each annular part 15a betweenthe central cylinder 12 of the protective member and an end fitting 13.The clamping surfaces 12c and 13g are sloped generally outwardlyandvaway from the adjacent end edge of the transparent tube 11.

Each gasket 15 is a deformable plastic material that is resistant to thefluids adapted to flow through the indicator. These materials are wellknown `to those skilled in the art and a suitable material in apolyethylene plastic.

As is shown in Figure 3, the gaskets 15 not only serve to seal thetransparent tube 11 to the protective member 10 but also serve to spacethe tube properly within the indicator. Thus the parts of the indicatorare so proportioned that portions of each gasket are partially eX-truded to provide this spacing. Thus each gasket includes a firstportion 15b extruded into the area between the tube 11 and theprotective member 10, a second portion 15e extruded around the inneredge of the tube 11 and a third portion 15d extruded between the washer16 and the adjacent inner surface of the protective member 10, A s canalso be seen most clearly in Figure 3, the edges of the tube 11 arechamfered in order to aid the extruding of the first and second portions15b and 15a` and in order to prevent a sharp edge of the tube cuttinginto each of these portions.

The indicator described and claimed herein is relatively small incross-sectional' area as can be seen from an inspection of the drawing.Furthermore, the parts are firmly sealed against leakage by positivepressure of the gaskets. Furthermore as each spring 17 applies pressureagainst both gaskets 15, one spring may be omitted if desired andsubstituted by a rigid backing member without sacrifice of pressure onthe gaskets. A more uniform sealing action is provided in this inventionas the gaskets bear against the ends ofthe tube 11 instead of againstthe sides thereof. These ends can be cut square to very close toleranceswhile the outside surface of transparent tubes and particularly of glasstubes often vary widely so that when the gaskets bear against theseouter surfaces uneven sealing is often achieved.

By attaching the outer annular parts of the gaskets 15 to the protectivemember 10 the inner ends of the springs 17, the washers 16 and the tube11 are all floating on the gaskets. This provides a firm yet yieldingstructure that avoids severe stresses and strains. Furthermore with thisstructure the tube 11 can be kept very short and does not need to be butonly slightly longer than the longitudinal length of the ports 12a. Inprior structures the transparent tubes often were required to berelatively long with the resulting magnifications of strains. As thetube is ordinarily the most fragile portion of the indicator thisavoidance of undue length and the resulting strains is very important inavoiding breakage.

Having described my invention as related to the ernbodiments shown inthe drawings, it is my intention that the invention be not limited byany of the details of description, unless otherwise specified, butrather be construed broadly within its spirit and scope as set out inthe accompanying claims.

I claim:

1. An indicator conduit apparatus, comprising: a transparent tube; asurrounding protective member within which the tube is located andcontaining ports through which the tube and contents are viewable; asealing gasket on each end edge of the tube; a washer on the side ofeach gasket on the side thereof opposite the tube; spring means urgingeach gasket into sealing contact with its end edge; and means sealingthe gaskets to the protective member on opposite sides of the ports, theoutside diameter of the tube being less than the inside diameter of theprotective member in the section adjacent to the tube and each gasketincluding a rst portion extruded into the area between the tube andprotective member, a second portion extruded around the inner edge ofthe tube, both extruded portions serving to yieldingly in place and athird portion extruded into the area between the washer and the insidewall of the protective member.

2. Anindicator conduit apparatus, comprising: a transparent tube havingend surfaces; a surrounding protective member within which the ,tube islocated and containing ports through which the tube and contents areviewable, the tube including said end surfaces being spaced from butclosely adjacent to the protective member; a distortable sealing gasketnormally in sealing contact against each end surface of the tube andagainst an adjacent annular surface of the protective member; a washermember bearing against each distortable sealing gasket V0n the sidethereof opposite the tube; and yieldable compression means normallybearing against each of said washer members on the side thereof oppositeto said gasket structure, each of said washer members including arelatively confinng annular portion including an inwardly directed ansedpart for pressing the gasket against .Said tube end surface under theurging of said yieldable compression member and a relatively open outerportion at the outer edge of the guide and confining member fordirecting the corresponding outer portion of the gasket into saidAsealing engagement with said annular portion of the protective memberunder the urging of said compression member.

3. An indicator Conduit apparatus, comprising: a transparent tube; asurrounding protective member with' in which the tube is located andcontaining ports .through which the tube and enntents viewable; asealing gasket on each end edge ef the tube; a washer on the side ofeach gasket on the side thereof opposite the tube; spring means urgingeach gasket into sealing Contact with its end edge; and means sealingthe gaskets to the protective member on opposite sides of the ports, theoutside diameter of the tube being less than the inside diatrilock thetube firmly yet eter of the protective member in the section adjacent tothe tube and each, gasket including a niet portion eX- truded into thearea between the tube and protective member, a second portionextrudedaround the inner edge of the tube, both extruded portions serving tolock the tube firmly yet yieldingly in place and a third portionextruded into the area between the washer and the inside wall of theprotective member, each washer including an annular ange of smallerdiameter than the corresponding end of the tube and extending inwardlythereof, said second extruded portion of the gasket being locatedbetween this flange and the tube.

4. An indicator conduit apparatus, comprising: a transparent tube; asurrounding protective member within which the tube is located andcontaining ports through which the tube and contents are viewable; asealing gas liet on each end edge of the tube; resilient means includingau annular member bearing on the side of cach gasket en .the Sidethereof opposite to the tube, said resillent means urging each gasketinto sealing Contact with its en tl edge; and means seating the gasketsto the protective member on opposite sides of the ports, the outsidediameter gf the tube being less than the inside diameter of theprotective member in the section adjacent to the tube and each gasketincluding a irst portion extruded into the area between the tube andprotective member, a second portion extruded around the inner edge ofthe tube, both extruded portions serving to lock the tube rmly yetyieldingly in place and a third portion extruded into the area betweenthe annular member and the inside wall of the protective member.

5. Au indicator conduit apparatus, comprising: a transparent tube; asurrounding protective member within which the tube is located andcontaining ports through which the tube and contents are viewable; asealing gasket on each end edge of the tube; resilient means includingan annular member bearing on the side of each gasket on the side thereofopposite to the tube, said re- Silient means urging each gasket intosealing contact with its end edge; and means sealing the gaskets to theprotective member on opposite sides of the ports, the outside diameterof the tube being less than the inside diameter of the protective memberin the section adjacent to the tube and each gasket including a firstportion extruded into the area between the tube and protective member,and a second portion extruded around the inner edge of the tube, bothextruded portions serving to lock bc tube firmly yet yieldingly inplace.

References Cited the tile of this patent UNETED STATES PATENTS 49,366Beleld Aug. l5, 1865 828,108 Graham Aug. 7, 1905 992,612 Stanton May 16,1911 1,666,918 Scoville Apr. 24, 1928 1,893,233 Hull Jan. 3, 19332,570,322 Christopher Oct. 9, 1951 2,624,308 Wittlin Jan. 6, 1953

